Recently, an elastic wave device including a plurality of high-frequency filters having different passbands has been used in, for example, a portable telephone. Filters whose frequency bands are near each other, for example, a filter having a passband of 1805 to 1880 MHz and a filter having a passband of 1930 to 1990 MHz are used. In such a case, a dual filter is used, which has a structure in which a balanced terminal is shared in order to share a circuit other than filters.
FIG. 6 is a schematic plan view of a conventional elastic wave device 101. Elastic wave device 101 includes low band side filter 103 and high band side filter 104 on piezoelectric substrate 2 made of piezoelectric single crystal. Low band side filter 103 is an unbalance/balance conversion type filter having passing characteristics in a band whose center frequency is relatively low. High band side filter 104 is an unbalance/balance conversion type filter having passing characteristics in a band whose center frequency is relatively high. Low band side filter 103 is connected to unbalanced terminal 5 at an input side. High band side filter 104 is connected to unbalanced terminal 6 at an input side. Furthermore, low band side filter 103 and high band side filter 104 are connected and shared to balanced terminal 7 and balanced terminal 8 at the output side.
Low band side filter 103 has longitudinally coupled elastic wave filters (longitudinally coupled elastic wave resonators) 51 and 52. High band side filter 104 has longitudinally coupled elastic wave filters 53 and 54.
Longitudinally coupled elastic wave filter 51 includes IDTs (Inter Digital Transducers) 51a, 51b, and 51c. Longitudinally coupled elastic wave filter 52 includes IDTs 52a, 52b, and 52c. Longitudinally coupled elastic wave filter 53 includes IDTs 53a, 53b, and 53c. Longitudinally coupled elastic wave filter 54 includes IDT 54a, 54b, and 54c. 
Phases of IDT 51a, IDT 51b, and IDT 51c of low band side filter 103 are the same as those of IDT 53a, IDT 53b, and IDT 53c of high band side filter 104. Furthermore, phases of IDT 52a, IDT 52b, and IDT 52c of low band side filter 103 are the same as those of IDT 54a, IDT 54b, and IDT 54c of high band side filter 104 (for example, PTL 1).